Rotary control shafts are oftentimes utilized in the control mechanisms for hydrostatic transmissions to selectively actuate the same. Various linkage systems have been proposed for use in such control mechanisms to effect such selective actuation of the control shaft. Conventional linkage systems are oftentimes unduly complex and place high stress concentrations on component parts thereof. In addition, relatively high initial starting torques are required to displace the control mechanisms from their neutral conditions of operation.
Also, conventional control mechanisims of this type are normally exposed to ambient conditions to thus give rise to potential lubrication and malfunctioning problems when they are exposed to dirt laden environments and the like. Furthermore, such control mechanisms do not provide means for assuring positive response to the control shafts upon high speed reversals of the rotary input shafts thereof.